Thermostatically-operated ammonia expansion valve



HIP. KEEN AND D. I1. HUYETT. v THERMOSTATICALLY OPERATED AMMONIA EXPANSION VALVE.

APPLICATION FILED IAN-'9. I920. r 1,408,744. I Patented Mar. 7,1922.

' 4 SHEETS-SHEET I- H. P. KEEN AND- D. D. HUYETT.

THEBMOSTATICALLY OPERATED AMMONIA EXPANSION VALVE- APPLICATION FILED JAN- 9, 1920.

1,408,744. Patented 1441,1922.

4 SHEETSSHEET Dana 'eZ Dhzg e 55.

H. P. KEEN AND D. D. HUYETT.

THEHMOSTA'TICALLY OPERATED AMMONIA EXPANSION VALVE. APPLICATION FILED JAN. 9. 1920.

, 1,408,744. Patented Mar. 7, 1922.

4 SHEETS-SHEET 3- ATTORNEY H. P. KEEN AND D. D. HUYETT.

THERMOSTATICALLY OPERATED AMMONIA EXPANSION VALVE. APPLICATION FILED JAN- 9, 1920.

1,408,744. Patented Mar. 7, 1922.

4 SHEETS-SHEET 4- By, 2; a; 5 X ATTORNEY UNITED STATES HAROLD PEROT KEEN, F BELLE'V'UE, DELAWARE, AND DAN ARDMORE, ZPENNSYLVANTA.

PATENT omen.

EL D. HUYE'IT, or

THERMOSTATICALLY-OPERATED AMMONIA EXPANSION VALVE.

Application filed January 9, 1920. Serial No.

' Thermostatically-Operated Ammonia Expansion Valve, of which the following is a specification.

The present invention relates to automatic expansion valves and has more especial relation to a thermostatically operated animonia expansion valve for use in connection with refrigeration plants of the intermittentabsorption type.

A number of automatic expansion valves are upon the market which are actuated by ammonia pressure in the expansion coils of a refrigerating system. Such pressure is known in the art as back or suction pressure. The temperature of expanding ammonia bears a given, fixed relation to its pressure in the expansion coils. Valves of the above type are primarily reducing valves and are similar in action to the well known type of steam reducing valves. Ammonia passes to such a valve lnthe form of liquid anhydrous at receiver pressure and is reduced 1n the expansion coils to a low pressure correspond ng to the temperature desire Experlence dictates, however, that valves actuated by ammonia pressure are not.

adaptable to the intermittentabsorption type of refrigerating apparatus for the rea son that back or suction pressure varies from 25" vacuum to 30 pounds pressure.

At the beginning of a refrigeration period the suction pressure is low while at the end of a period this pressure is high.

The leading object of the present invention may be said to be to provide an expansion valve controlled directly by temperature of the medium being cooled, as for instance a cold-storage room, brine tank, Water cooler '01 the like. 7 A further object is to provide a thermostatically operated expansion valve whereby when temperature of the air in the.

medium to be cooled increases slightly above desired temperature a thermostat opens the expansion valve thus allowing liquid, ammonia to flow to the expansion coils, and when temperature has been reduced to de- Specification of Let ers Patent.

Patented Marat, 1922.

ammonia. A further object is to provide an,

expansion valve constructed to open and close in an evenly balanced manner irrespective of the pressure present at the ammonia inlet and outlet. A still further ob- JGCtis to provide an ammonia expansion valve in which friction causing parts are reduced to a minimum. Other and further objects reside in the provision of a certain new and novel arrangement and. combination of parts for commercially bettering the class of valves under consideration.

The invention consists of the improvements hereinafter described and finally claimed.

The nature, characteristic features and scope of the invention will be more fully understood from the following description taken in connection with the accompanying drawings forming part hereof, and which:

Fig. 1, is a view in elevation of the thermostatically operated ammonia expansion valve embodying features of the invention.

Fig. 2, is a detail view, in central section, of the valve parts detached from the-operating medium.

Fig. 3, is a detached'view, in elevation of results, although it is to be understood that the various instrumentalities of which our invention consists can be variously arranged and organized and that our invention is not limited to the precise arrangement and organization of the instrumentalitiesas here .in shown and described.

In the drawings 10 designates a valve casmg which is provided with an ammonia liquid inlet 11 and an outlet 12 leading to expansion coils a. The casing 10 is flanged '30 i Clamped between at each end, a plate 13 being bolted to one flange and a bonnet 14 being bolted to the other. Within the casing and preferably formed integral therewith is a neck 15 having a passage therein parallel and in register, at one end, with inlet 11. The other end is in communication with a passage 16 at right angles thereto and which is extended through a member 17 having a valve-seat 18 therein for accommodating a valve-spindle 19. This member 17 is removably fixed to neck 15 and has a passage 20 therethrough at right angles to passage 16 and communicating therewith. A yoke 21 is located within casing 10 and is adapted to straddle neck 15 and member 17 at right angles thereto and adjustablv carries at one end the valvespindle'19. The other end of yoke 21 is guided by a pin and slot connection 21' within an opening in one end of casing 10. Valve-spindle 19, traveling with respect to its valve seat, serves to guide the other end ofsaid yoke. Sufficient play between parts is allowed in order that the valve-spindle be self-centering. lamped between the plate 13 and one, end of casing 10 is a diaphragm 22, the casing end and plate being recessed to permit movement of the diaphragm whichis thermostatically operated in a manner to presently appear. the opposite end of casing 10 and the bonnet 14 is another diaphragm 23 which is directly opposed by a spring 24 contained within said bonnet. The tension of spring 24 may be regulated by screw 25. The ends of yoke 21 abut with diaphragms 22 and 23 respectively so that inward movev soldered thereto.

ment of diaphragm 22 serves to move valvespindle 19 away from its seat against the action of spring 24 which normally tends to hold said-spindle against said seat:

A description will now be given of the thermostatic control for operating diaphragm 22. 26 designates a seamless, drawn steel tube. exteriorly provided with a plurality of disc-like fins 27 of copper gauze One end of tube 26 is in communication with a coil 28 formed of seamless steel tubing which in turn c'ommunicates with an opening 29 passing through plate 13 and is in register with the recessed portion thereof opposite the sensitive, steel diaphragm 22.' Tube 26 andcoil 28 are filled with liquid anhydrous ammonia which is fed through a manually operated chargingvalve 30 carried by the free end of tube 26. This liquid, when heated to 95, exerts a pressureof about 185 pounds per square inch and if reduced to zero exerts a pressure of only 15 pounds. At other temperatures-this liquid exerts a corresponding pressure according to the physical properties of anhydrous ammonia. Pressure a generated in the thermostat serves to operate.

the diaphragm 22.

back and forth .ture takes place from time to that of the-air or The operation of the above described thermostatically operated ammonia expansion valve may be described as follows:--When I stat to exert considerable pressure upon dia-,

phragm 22 with the result that valve-spindle 19 is caused to recede to its full extent from its seat. Liquid ammonia, under such conditions, expands into the coils of the refrigerating apparatus and refrigeration takes place with consequent lowering of room temperature- With lowering of room temperature, pressure in the themostat decreases with the result that spring 24 causes diaphragm 23, through yoke 21, to move valvespindle 19 against its seat, thus cutting oil the flow of liquid ammonia to the .coils. Obviously as rise and fall of time the thermostat is so affected that liquid ammonia is permitted or denied passage through the expansion valve. Inthis connection it is to be observed that the fins upon the tube of the thermostat function ateheat so that a rapid heat interchange is made between the ammonia within the tube and air surrounding the tube thus adding to the; sensitiveness of the thermostat. The purpose of the coiled tubing is to preclude frost-creep between the expansion valve and thermostat. When refrigeration is taking place, the valve is covered with frost reaching a temperature much below valve temperature will not pass to the thermostat. Otherwise such temperature-would room temperato absorb and radi- 1 other substance to be cooled-., v The coiled tubing is of such length tha't"th'e 'T.

tend to lower the temperature of the anhydrous ammbn'ia contained within the thermostat with the result that the valve would imy i'operly function.

ith the initial reduction of room temperature, with the valve wide open as described, there is a tendency for too much liquid ammonia to pass to the coils with the result that a certain percentage of refrigerant is wasted before room comes low enough to affect the thermostat. Currents of warm air, due to various causes, may also be present in the room which .also tend to cause the valve-spindle to be unduly temperature beremoved from its seat. To overcome thesev objectionable features wehave designed a stop device which may be set to permit a maximum size expansion coil or' refrigerati ng-box.

flow of liquid suitable for a given v Having screw threaded relation with adjust- 1 valve-spindle from its seat will permit of considerable refrigeration. The maximum movement in largest types of intermittentabsorption refrigeration apparatus does not exceed a few thousandths of an inch. Themaximum movement of the present diaphragm and valve-spindle is about one sixteenth of an inch. As the opening through, the valve-seat is relatively small there is a.

' tendencyfor said seat to'olog with fine particles of matter suspended in the liquid am-' monia. If the valve-spindle is withdrawn to its full extent, however, this foreign matbe readily purged from the valvev ter' ma;

seat. his may be accomplished through the instrumentality of the stop-device scribed. i I r We have shown in the drawings several ways of employingfthe thermostat in conjust denection with the expansion valve. In Fig. 5

. I as desired. 7

the thermostat is shown exposed either to ai*r..brine orotherliquidto be cooled. In 35 Fig. 6, the copper gauze fins are dispensed with and the tube contained'within the ammonia. suction line which? carries expanded, vapors from the ammoniacoils toythe generator-absorber-. When such vapers reach a predetermined low temperature the valve spindle is seated to close the flow of vapors.

As the vapors rise in temperature the-valvespindle wlthdraws from its seat. By such arrangement, with proper proportioning of the expansion coils and proper adjusting of spring in the bonnet, temperature'of a refrigerating compartment may be 'reglmated.

It will now be apparent that-we have de-. vised a novehand usefulconstruction which embodies the'features: of advantage enumerated as desirable in the statement of thein vfentipn and the-above description and while I we have in the present instance shown and described thepreferred embodiment thereof which hasbeen found in practice to' give satisfactor andrelieble' results, it is 'to be amderst that the same issusceptible of modification in various particulars, without depa t g f m h .tioning to operate the other of and I spirit orscope of the vention or sacrificing any of itsadvantages. 7

What we claim is:-- i s 1. In apparatus of the character stated the combination of expansion coils, an expansible fluid 'feed line to said coils, an expansion valve located in said line, a thermostat-tubecontalning expansible fiuid responsive to changes intemperature of a system being cooled and closely coiled piping interposed between and communicating with the expansion valve and said thermostat-tube said piping serving. as an insulator .to prevent low temperature being conducted from said "valve to said thermostat-tube.

,2. Inapparatus of the character stated the combinatlon of-expansion coils, an expansible fluid feed line to said coils, an expansion.

valve located in said line, said valve being equipped with spaced diaphragms arranged to be balanced against the pressure of said expansible fluid, said diaphragms having valvular means operatively connected therebetween, means for causi one of said dia= phragms to maintain sai valvular means closed, a thermostat-tube containing expan sible fluid responsive tochanges in temperature of system being cooled and closely coiled piping inter osed'between and communicating with t e expansion valve and said thermostat-tube said piping serving as an insulator to prevent low temperature being conducted from said valve to said thermostat-tube, said thermostatic means funcsaid dia phragms for openin said valvular means. 3.1 n

apparatus 0 the character stated the combination of expansion coils, an expansible fluld feed line to said coils, an, expanslen valve located in said line said valve beingequipped with spaced diaphragms arranged to be balanced against the ressure of said expansible fluid, said diap ragms having.

between; means for 'causin one of said dia- 'phragms to mainta n sai K valvular means valvular means operatively connected thereclosed; a thermostat-tube containingexpanture of a system being cooled and closely coiled piping inter d between and communicating with t e expansion valve and,

said thermostat-tube said piping serving as an insulator to preventlow temperature be-- -'ing conducted from said valve to said thermostat-tube, said thermostatic means func-' tioning to operate the other of said diaphragms foropening' said valvular means,

.a predetermined opening of said valvular means. i

means for obtaining sible fluid responsive to changes in tempera- In itness whereof we have herewith I signed our names.

n HAROLD PEROT KEEN. .DANIEL'D. 

